// Copyright 2019 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package dml

import "strings"

// GenColumnPlaceholders generates placeholders in question mark format,like "?,?,?".
func GenColumnPlaceholders(length int) string {
	var b strings.Builder
	b.Grow(2 * length)
	for i := 0; i < length; i++ {
		if i > 0 {
			b.WriteByte(',')
		}
		b.WriteByte('?')
	}
	return b.String()
}
